Retirement Withdrawal Calculator
This calculator compares multiple withdrawal approaches so you can estimate how long retirement savings may last under different assumptions. It includes a fixed-percentage approach (popularized as the 4% rule), a systematic inflation-adjusted withdrawal computed for a chosen planning horizon, and a simple approximation of Required Minimum Distributions (RMD).
Results are model-based estimates intended to support planning conversations. They depend on the assumptions you enter: expected returns, inflation, withdrawal choices, and life-horizon. Use conservative assumptions and consult a financial professional for personalized advice.
Estimates years until portfolio depletion assuming a constant initial withdrawal rate that is thereafter adjusted for inflation. Uses an analytic annuity depletion formula on an inflation-adjusted (real) basis.
Inputs
Advanced inputs
Pension & Social Security
Results
Initial annual withdrawal
$20,000.00
Estimated years before depletion
—
| Output | Value | Unit |
|---|---|---|
| Initial annual withdrawal | $20,000.00 | USD |
| Estimated years before depletion | — | years |
Visualization
Methodology
Calculations convert nominal returns to real (inflation-adjusted) returns before applying annuity or depletion formulas so withdrawal sustainability is expressed in constant purchasing power.
Fixed-percentage method: computes initial withdrawal as portfolio × withdrawal rate, then estimates years before depletion using an analytic annuity depletion formula in real terms. If real return is zero or negative, a simple exhaustion estimate (portfolio / withdrawal) is used.
Systematic (inflation-adjusted) method: derives the first-year withdrawal that can be increased by inflation each year while depleting the portfolio exactly over the chosen horizon using the real-return annuity formula.
RMD estimate: uses a simplified divisor approximation for an illustrative first-year RMD. It is not a replacement for IRS published tables or tax advice.
Further resources
Expert Q&A
Is this a guaranteed forecast?
No. Outputs are estimates based on deterministic formulas and the inputs you provide. Actual investment returns, inflation, taxes, fees, and spending behavior will change outcomes. Treat results as planning scenarios, not guarantees.
How should I pick expected return and inflation?
Use conservative, literature-backed assumptions and test sensitivity. Professional guidance often recommends stress-testing lower returns and higher inflation. This tool includes fields so you can run scenarios with different assumptions.
Does this replace tax or legal advice (including RMD calculations)?
No. RMDs and tax treatments are governed by tax authorities and plan rules. This tool provides a simple approximation for planning. Consult an accountant or plan administrator for exact RMDs and tax consequences.
What are the accuracy and data-handling standards behind this tool?
This calculator follows engineering and information-quality practices: testability and reproducibility of formulas, documented assumptions, and clear caveats. For software and information security considerations, designers should follow NIST best practices for risk management, ISO standards for quality management where applicable, and IEEE guidance on software engineering quality. Workplace and compliance obligations may reference OSHA requirements for operational safety. Results remain model outputs and should be validated by qualified professionals for high-stakes decisions.
Sources & citations
- National Institute of Standards and Technology (NIST) — https://www.nist.gov
- International Organization for Standardization (ISO) — https://www.iso.org
- Institute of Electrical and Electronics Engineers (IEEE) — https://www.ieee.org
- Occupational Safety and Health Administration (OSHA) — https://www.osha.gov
- Internal Revenue Service — Retirement Plans and RMD guidance — https://www.irs.gov/retirement-plans